I just bought some flex on stirrups and they've made a huge difference in my riding. I feel so much more secure and I can get my heels down further and with the spikes, I never lose a stirrup. Highly recommend!
I recently bought FreeJump stirrups. I absolutely love them. My feet feel secure but I know that if something happens and I end up falling off, my foot won't get stuck in the stirrup thanks to the safety feature. Definitely worth the money.